turning again, we rode forward, casting shadows far before us. It was twenty miles to the next water, and in hot weather the journey across this waterless, shadeless, sandy stretch of country is hard on the mules and oxen. But on this day the sky speedily grew overcast and a cool wind blew in our faces as we travelled at a quick, running walk over the immense rolling plain. The ground was sandy; it was covered with grass and with a sparse growth of stunted, twisted trees, never more than a few feet high. There were rheasostrichesand small pampas-deer on this plain; the coloration of the rheas made it difficult to see them at a distance, whereas the bright red coats of the little deer, and their uplifted flags as they ran, advertised them afar off. We also saw the footprints of cougars and of the small-toothed, big, red wolf. Cougars are the most inveterate enemies of these small South American deer, both those of the open grassy plain and those of the forest.

It is not nearly as easy to get lost on these open plains as in the dense forest; and where there is a long, reasonably straight road or river to come back to, a man even without a compass is safe. But in these thick South American forests, especially on cloudy days, a compass is an absolute necessity. We were struck by the fact that the native hunters and ranchmen on such days continually lost themselves and, if permitted, travelled for miles through the forest either in circles or in exactly the wrong direction. They had no such sense of direction as the forest-dwelling Ndorobo hunters in Africa had, or as the true forest-dwelling Indians of South America are said to have. On certainly half a